Cogeneration system

Abstract

In a cogeneration system having a generation unit equipped with a generator and an internal combustion engine, there is installed with a hot water unit including a first flow channel connecting a water supply source with a thermal load, a heat exchanger exchanging heat between water flowing the first flow channel and engine coolant, a first electromagnetic solenoid regulating flow rate of the water heated by the heat exchanger, a second flow channel connected to the first flow channel, a boiler heating water flowing through the second flow channel, and a second electromagnetic solenoid regulating flow rate of the water to be heated by the boiler. The temperatures of the engine coolant and water at the first and second flow channel joint are detected and operation of the first and second valves is controlled based on the detected temperatures, rendering hot water tank unnecessary, thereby achieving the compact structure.

1. A cogeneration system having a generation unit equipped with a generator adapted to be connectable to an AC power feed line between a commercial power network and an electrical load, and an internal combustion engine for driving the generator, comprising:
 a hot water unit including:
 a first flow channel that connects a water supply source with a thermal load to supply water from the water supply source to the thermal load; 
 a heat exchanger that is installed in the first flow channel and exchanges heat between the water flowing through the first flow channel and coolant of the engine; 
 a first electromagnetic solenoid valve that is installed in the first channel and regulates flow rate of the water heated by the heat exchanger; 
 a second flow channel connected to the first flow channel to form a bypass between the heat exchanger and the first solenoid valve; 
 a boiler that is installed in the second flow channel and heats water flowing through the second flow channel; and 
 a second electromagnetic solenoid valve that is installed in the second flow channel and regulates flow rate of the water to be heated by the boiler; and 
 
 an electronic control unit that detects at least one of a temperature of the coolant of the engine and a temperature of water at a joint where the first and second flow channels are joined and controls operation of the first and second solenoid valves based on the detected temperatures. 
 
     
     
       2. The system according to  claim 1 , wherein the electronic control unit detects the temperature of the coolant of the engine and controls operation of the first solenoid valve such that the detected temperature of the coolant becomes a prescribed temperature. 
     
     
       3. The system according to  claim 1 , wherein the electronic control unit detects the temperature of the water at the joint and controls operation of the second solenoid valve such that the detected temperature of the water becomes a prescribed temperature. 
     
     
       4. The system according to  claim 1 , further including:
 a current detector that is installed in the power feed line and detects current flowing through the power feed line, 
 wherein the electronic control unit opens only the second solenoid valve when the detected current is less than a predetermined value. 
 
     
     
       5. The system according to  claim 1 , further including:
 a mixing valve that is installed on downstream of the joint and mixes the water flowing through the first flow channel with water from the water supply source, 
 wherein the electronic control unit controls operation of the mixing valve so that a temperature of water at a position downstream of the mixing valve becomes equal to a predetermined temperature. 
 
     
     
       6. A cogeneration system having a generation unit equipped with a generator adapted to be connectable to an AC power feed line between a commercial power network and an electrical load, and an internal combustion engine for driving the generator, comprising:
 a hot water unit including:
 a first flow channel that connects a water supply source with a thermal load to supply water from the water supply source to the thermal load; 
 a heat exchanger that is installed in the first flow channel and exchanges heat between the water flowing through the first flow channel and coolant of the engine; 
 a first electromagnetic solenoid valve that is installed in the first channel and regulates flow rate of the water heated by the heat exchanger; 
 a second flow channel connected to the first flow channel to form a bypass between the heat exchanger and the first solenoid valve; 
 a boiler that is installed in the second flow channel and heats water flowing through the second flow channel; and 
 a second electromagnetic solenoid valve that is installed in the second flow channel and regulates flow rate of the water to be heated by the boiler; 
 
 an electronic control unit that detects at least one of a temperature of the coolant of the engine and a temperature of water at a joint where the first and second flow channels are joined and controls operation of the first and second solenoid valves based on the detected temperatures; and 
 a mixing valve that is installed on downstream of the joint and mixes the water flowing through the first flow channel with water from the water supply source, 
 wherein the electronic control unit controls operation of the mixing valve so that a temperature of water at a position downstream of the mixing valve becomes equal to a predetermined temperature. 
 
     
     
       7. The system according to  claim 6 , wherein the electronic control unit detects the temperature of the coolant of the engine and controls operation of the first solenoid valve such that the detected temperature of the coolant becomes a prescribed temperature. 
     
     
       8. The system according to  claim 6 , wherein the electronic control unit detects the temperature of the water at the joint and controls operation of the second solenoid valve such that the detected temperature of the water becomes a prescribed temperature. 
     
     
       9. The system according to  claim 6 , further including: a current detector that is installed in the power feed line and detects current flowing through the power feed line, wherein the electronic control unit opens only the second solenoid valve when the detected current is less than a predetermined value. 
     
     
       10. A cogeneration system having a generation unit equipped with a generator adapted to be connectable to an AC power feed line between a commercial power network and an electrical load, and an internal combustion engine for driving the generator, comprising:
 a hot water unit including:
 a first flow channel that connects a water supply source with a thermal load to supply water from the water supply source to the thermal load; 
 a heat exchanger that is installed in the first flow channel and exchanges heat between the water flowing through the first flow channel and coolant of the engine; 
 a first electromagnetic solenoid valve that is installed in the first channel and regulates flow rate of the water heated by the heat exchanger; 
 a second flow channel connected to the first flow channel to form a bypass between the heat exchanger and the first solenoid valve; 
 a boiler that is installed in the second flow channel and heats water flowing through the second flow channel; and 
 a second electromagnetic solenoid valve that is installed in the second flow channel and regulates flow rate of the water to be heated by the boiler; 
 
 an electronic control unit that detects at least one of a temperature of the coolant of the engine and a temperature of water at a joint where the first and second flow channels are joined and controls operation of the first and second solenoid valves based on the detected temperatures; and 
 a current detector that is installed in the power feed line and detects current flowing through the power feed line, 
 wherein the electronic control unit opens only the second solenoid valve when the detected current is less than a predetermined value. 
 
     
     
       11. The system according to  claim 10 , wherein the electronic control unit detects the temperature of the coolant of the engine and controls operation of the first solenoid valve such that the detected temperature of the coolant becomes a prescribed temperature. 
     
     
       12. The system according to  claim 10 , wherein the electronic control unit detects the temperature of the water at the joint and controls operation of the second solenoid valve such that the detected temperature of the water becomes a prescribed temperature. 
     
     
       13. The system according to  claim 10 , further including:
 a mixing valve that is installed on downstream of the joint and mixes the water flowing through the first flow channel with water from the water supply source, 
 wherein the electronic control unit controls operation of the mixing valve so that a temperature of water at a position downstream of the mixing valve becomes equal to a predetermined temperature.